Fertilising guide
How to fertilise Alaska Mix Nasturtium (Tropaeolum majus)— schedule & NPK
Also called Nasturtium, Garden Nasturtium, Alaska Nasturtium.
More about alaska mix nasturtium
About Alaska Mix Nasturtium
Tropaeolum majus · also called Nasturtium, Garden Nasturtium · flowering
A bushy, mounding nasturtium with distinctive cream-marbled foliage and brightly coloured edible flowers in orange, red, and yellow. Reaches 25–35 cm tall. Thrives in poor soil and full sun. Flowers and leaves are edible with a peppery flavour. Considered mildly toxic to cats and dogs in large quantities.
Growth habit: Compact mounding annual
Watch for — Poor flowering in rich soil: The most common issue; avoid adding compost or fertiliser to the planting area.
What fertiliser alaska mix nasturtium actually wants — and why
Alaska Mix Nasturtium is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for alaska mix nasturtium: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed alaska mix nasturtium, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For alaska mix nasturtium:
Avoid feeding altogether in average garden soil. In very poor sandy soil, a single dilute balanced application at planting is sufficient. More fertiliser causes all-leaf, no-flower growth. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when alaska mix nasturtium is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for alaska mix nasturtium
Half strength is the safe default for alaska mix nasturtium — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water alaska mix nasturtium first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the alaska mix nasturtium watering schedule.
Signs you are over-feeding alaska mix nasturtium
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for alaska mix nasturtium:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding alaska mix nasturtium
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full alaska mix nasturtium care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of alaska mix nasturtium with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for alaska mix nasturtium
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising alaska mix nasturtium — frequently asked questions
What fertiliser does alaska mix nasturtium need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Alaska Mix Nasturtium is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed alaska mix nasturtium?
Avoid feeding altogether in average garden soil. In very poor sandy soil, a single dilute balanced application at planting is sufficient. More fertiliser causes all-leaf, no-flower growth. Avoid feeding altogether in average garden soil. In very poor sandy soil, a single dilute balanced application at planting is sufficient. More fertiliser causes all-leaf, no-flower growth. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for alaska mix nasturtium?
Half strength is the safe default for alaska mix nasturtium — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding alaska mix nasturtium look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding alaska mix nasturtium year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of alaska mix nasturtium?
Flush the pot of alaska mix nasturtium with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Alaska Mix Nasturtium care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water alaska mix nasturtium — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
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- All 11687 fertilising guides in the Growli library